Reference for Kiddushin 65:7
ותו בר קפרא ואמרי לה ר' שמואל בר ר' יוסי הוה יתיב בי מסחותא על ואזיל ר' שמעון בר רבי ולא קם מקמיה ואיקפד ואתא א"ל לאבוה שני שלישי שליש שניתי לו בתורת כהנים ולא עמד מפני ואמר לו שמא בהן יושב ומהרהר
The Master said: 'I might think that one must rise up before him out of a privy or a bath-house.' Is it then not so? But R'Hiyya was sitting in a bath-house, when R'Simeon son of Rabbi passed by, but he did not rise before him, whereat he was offended and went and complained to his father, 'I taught him two-fifths of the Book of Psalms,<span class="x" onmousemove="('comment',' So Rashi. Tosaf.: Two books of the five into which it may be divided, viz., Chs. I-XLI, XLII-LXXII, LXXIII-LXXXIX, XC-CVI, CVII-CL. Each of these divisions end with 'amen,' except the last, which marks the end of the book as a whole, ohbvf ,ru,');"><sup>11</sup></span>